Physiological vibration detection in an implanted medical device

Abstract

An embodiment of an implantable system configured to be implanted in a patient includes an accelerometer, a neural stimulator, and a controller. The neural stimulator is configured to deliver neural stimulation to a neural target. The controller is configured to use the accelerometer to detect laryngeal vibration or coughing, and is configured to deliver a programmed neural stimulation therapy using the neural stimulator and using detected laryngeal vibration or detected coughing as an input to the programmed neural stimulation therapy.

What is claimed is: 
     
       1. An implantable system configured to be implanted in a patient, comprising:
 an accelerometer; 
 a neural stimulator configured to deliver neural stimulation to a neural target; and 
 a controller configured to use the accelerometer to detect laryngeal vibration, and configured to deliver a programmed neural stimulation therapy using the neural stimulator and using detected laryngeal vibration as an input to the programmed neural stimulation therapy, 
 wherein the neural stimulator is configured to deliver the neural stimulation at a neural stimulation frequency, the system further comprising a bandpass filter configured to filter an accelerometer signal to the neural stimulation frequency to detect laryngeal vibration modulated at the neural stimulation frequency, and 
 wherein the controller is configured to use the accelerometer to detect cough, to deliver the neural stimulation with a programmed duty cycle including a stimulation ON portion and a stimulation OFF portion, to monitor an accelerometer signal for a cough during the ON portion, and to titrate the neural stimulation therapy if the cough occurs during the ON portion of the neural stimulation therapy. 
 
     
     
       2. The system of  claim 1 , wherein the controller is configured to deliver the neural stimulation with a programmed duty cycle including a stimulation ON portion and a stimulation OFF portion, to deliver a plurality of neural stimulation pulses during the stimulation ON portion, and to monitor a window of time after a neural stimulation pulse for laryngeal vibration over a threshold. 
     
     
       3. The system of  claim 2 , wherein the controller is further configured to monitor for laryngeal vibration after each neural stimulation pulse during the stimulation ON portion, and to titrate the neural stimulation therapy if laryngeal vibration occurs more than a threshold number of times during the stimulation ON portion. 
     
     
       4. The system of  claim 1 , wherein the controller is configured to use the accelerometer to detect cough, and to adjust an intensity of the neural stimulation therapy to a level where laryngeal vibration is detected and cough is not detected. 
     
     
       5. An implantable system configured to be implanted in a patient, comprising:
 an accelerometer; 
 a neural stimulator configured to deliver neural stimulation to a neural target; and 
 a controller configured to use the accelerometer to detect laryngeal vibration or coughing, and configured to deliver a programmed neural stimulation therapy using the neural stimulator and using detected laryngeal vibration or detected coughing as an input to the programmed neural stimulation therapy, wherein the controller is configured to use the accelerometer to detect heart sounds and to use the detected heart sounds to provide an input to the neural stimulation therapy, wherein the controller is configured to determine left ventricular ejection time (LVET) using the detected heart sounds and to use the LVET to provide an input to the neural stimulation therapy. 
 
     
     
       6. A method, comprising:
 using an accelerometer to detect laryngeal vibration or coughing; and 
 controlling a neural stimulation therapy using detected laryngeal vibration as an input to the neural stimulation therapy, wherein the neural stimulation therapy is delivered with a neural stimulation frequency, the method further comprising bandpass filtering an accelerometer signal to the neural stimulation frequency to detect laryngeal vibration modulated at the neural stimulation frequency, 
 wherein the accelerator is used to detect cough, the neural stimulation therapy is delivered with a programmed duty cycle, the programmed duty cycle including an ON portion and an OFF portion, and the neural stimulation therapy delivers a plurality of neural stimulation pulses during the ON portion, the method further comprises monitoring an accelerometer signal for a cough during the ON portion, and titrating the neural stimulation therapy if the cough occurs during the ON portion of the neural stimulation therapy. 
 
     
     
       7. The method of  claim 6 , wherein the neural stimulation therapy is delivered with a programmed duty cycle, the programmed duty cycle including a stimulation ON portion and a stimulation OFF portion, and the neural stimulation therapy delivers a plurality of neural stimulation pulses during the stimulation ON portion, the method further comprises monitoring a window of time after a neural stimulation pulse for laryngeal vibration over a threshold. 
     
     
       8. The method of  claim 7 , further comprising monitoring for laryngeal vibration after each neural stimulation pulse, and titrating the neural stimulation therapy if laryngeal vibration occurs more than a threshold number of times during the stimulation ON portion. 
     
     
       9. The method of  claim 6 , wherein the accelerometer is used to detect cough, and controlling the neural stimulation therapy includes adjusting an intensity of the neural stimulation therapy to a level where laryngeal vibration is detected and cough is not detected. 
     
     
       10. The method of  claim 6 , wherein controlling the neural stimulation therapy includes:
 receiving a manual input from a clinician to initiate a titration process; 
 periodically initiating the titration process; or 
 initiating the titration process in response to detecting a cough or laryngeal vibration. 
 
     
     
       11. The method of  claim 6 , wherein controlling the neural stimulation therapy includes limiting an increase of neural stimulation intensity to an upper bound. 
     
     
       12. The method of  claim 6 , wherein controlling the neural stimulation using detected laryngeal vibration or detected coughing includes offsetting an intensity of the neural stimulation from a first threshold level at which laryngeal vibration was detected or a second threshold level at which coughing was detected. 
     
     
       13. A method, comprising:
 using an accelerometer to detect laryngeal vibration or coughing; 
 controlling a neural stimulation therapy using detected laryngeal vibration or detected coughing as an input to the neural stimulation therapy; 
 using the accelerometer to detect heart sounds; 
 using the detected heart sounds to provide an input to the neural stimulation therapy; 
 determining left ventricular ejection time (LVET) using the detected heart sounds; and 
 using the LVET to provide an input to the neural stimulation therapy. 
 
     
     
       14. An implantable system configured to be implanted in a patient, comprising:
 an accelerometer; 
 a neural stimulator configured to deliver neural stimulation to a neural target; and 
 a controller configured to use the accelerometer to detect laryngeal vibration, and configured to deliver a programmed neural stimulation therapy using the neural stimulator and using detected laryngeal vibration as an input to the programmed neural stimulation therapy, 
 wherein the neural stimulator is configured to deliver the neural stimulation at a neural stimulation frequency, the system further comprising a bandpass filter configured to filter an accelerometer signal to the neural stimulation frequency to detect laryngeal vibration modulated at the neural stimulation frequency, 
 wherein the controller is configured to use the accelerometer to detect cough, and to adjust an intensity of the neural stimulation therapy to a level where laryngeal vibration is detected and cough is not detected. 
 
     
     
       15. The system of  claim 14 , wherein the controller is configured to deliver the neural stimulation with a programmed duty cycle including a stimulation ON portion and a stimulation OFF portion, to deliver a plurality of neural stimulation pulses during the stimulation ON portion, and to monitor a window of time after a neural stimulation pulse for laryngeal vibration over a threshold. 
     
     
       16. The system of  claim 15 , wherein the controller is further configured to monitor for laryngeal vibration after each neural stimulation pulse during the stimulation ON portion, and to titrate the neural stimulation therapy if laryngeal vibration occurs more than a threshold number of times during the stimulation ON portion. 
     
     
       17. A method, comprising:
 using an accelerometer to detect laryngeal vibration or coughing; and 
 controlling a neural stimulation therapy using detected laryngeal vibration as an input to the neural stimulation therapy, wherein the neural stimulation therapy is delivered with a neural stimulation frequency, the method further comprising bandpass filtering an accelerometer signal to the neural stimulation frequency to detect laryngeal vibration modulated at the neural stimulation frequency, 
 wherein the accelerometer is used to detect cough, and controlling the neural stimulation therapy includes adjusting an intensity of the neural stimulation therapy to a level where laryngeal vibration is detected and cough is not detected. 
 
     
     
       18. The method of  claim 17 , wherein the neural stimulation therapy is delivered with a programmed duty cycle, the programmed duty cycle including a stimulation ON portion and a stimulation OFF portion, and the neural stimulation therapy delivers a plurality of neural stimulation pulses during the stimulation ON portion, the method further comprises monitoring a window of time after a neural stimulation pulse for laryngeal vibration over a threshold. 
     
     
       19. The method of  claim 18 , further comprising monitoring for laryngeal vibration after each neural stimulation pulse, and titrating the neural stimulation therapy if laryngeal vibration occurs more than a threshold number of times during the stimulation ON portion. 
     
     
       20. The method of  claim 17 , wherein controlling the neural stimulation therapy includes:
 receiving a manual input from a clinician to initiate a titration process; 
 periodically initiating the titration process; or 
 initiating the titration process in response to detecting a cough or laryngeal vibration. 
 
     
     
       21. The method of  claim 17 , wherein controlling the neural stimulation therapy includes limiting an increase of neural stimulation intensity to an upper bound. 
     
     
       22. The method of  claim 17 , wherein controlling the neural stimulation using detected laryngeal vibration or detected coughing includes offsetting an intensity of the neural stimulation from a first threshold level at which laryngeal vibration was detected or a second threshold level at which coughing was detected. 
     
     
       23. A method, comprising:
 using an accelerometer to detect laryngeal vibration or coughing; and 
 controlling a neural stimulation therapy using detected laryngeal vibration as an input to the neural stimulation therapy, wherein the neural stimulation therapy is delivered with a neural stimulation frequency, the method further comprising bandpass filtering an accelerometer signal to the neural stimulation frequency to detect laryngeal vibration modulated at the neural stimulation frequency, 
 wherein controlling the neural stimulation using detected laryngeal vibration or detected coughing includes offsetting an intensity of the neural stimulation from a first threshold level at which laryngeal vibration was detected or a second threshold level at which coughing was detected. 
 
     
     
       24. The method of  claim 23 , wherein the neural stimulation therapy is delivered with a programmed duty cycle, the programmed duty cycle including a stimulation ON portion and a stimulation OFF portion, and the neural stimulation therapy delivers a plurality of neural stimulation pulses during the stimulation ON portion, the method further comprises monitoring a window of time after a neural stimulation pulse for laryngeal vibration over a threshold. 
     
     
       25. The method of  claim 23 , further comprising monitoring for laryngeal vibration after each neural stimulation pulse, and titrating the neural stimulation therapy if laryngeal vibration occurs more than a threshold number of times during the stimulation ON portion. 
     
     
       26. The method of  claim 23 , wherein controlling the neural stimulation therapy includes:
 receiving a manual input from a clinician to initiate a titration process; 
 periodically initiating the titration process; or 
 initiating the titration process in response to detecting a cough or laryngeal vibration. 
 
     
     
       27. The method of  claim 23 , wherein controlling the neural stimulation therapy includes limiting an increase of neural stimulation intensity to an upper bound.